US Patent 10921630 Spatially variable liquid crystal diffraction gratings

The present disclosure relates to display systems and, more particularly, to augmented reality display systems. A diffraction grating includes a plurality of different diffracting zones having a periodically repeating lateral dimension corresponding to a grating period adapted for light diffraction. The diffraction grating additionally includes a plurality of different liquid crystal layers corresponding to the different diffracting zones. The different liquid crystal layers have liquid crystal molecules that are aligned differently, such that the different diffracting zones have different optical properties associated with light diffraction.